A conventional technique of rendering a figure respectively in areas into which a rendering area of a graphic screen is divided, is known. For example, according to a known technique, when the required clip size exceeds the available clip size, a current black-and-white image rendering command is divided into divided black-and-white image rendering commands and a current color image rendering command is divided according to areas corresponding to the divided black-and-white image rendering commands. According to another known technique, a rendering command for rendering in one page is divided into multiple bands, band heights are determined temporarily in order for each band to keep band heights equal to or lower than a threshold value, and a list of graphic displays for one page is distributed to multiple bands. According to still another known technique, a print command to a printer is generated based on rendering range information created by dividing a rendering range, in which a figure is to be rendered, into multiple ranges and on bit-map data written in an intermediate language based on a print command from an application program, and the generated print command is sent to the printer. According to yet another known technique, when a rendering memory area for an application program cannot be established, a rendering memory area for a priority-given application program is established preferentially and rendering memory areas for other application programs are established according to a value obtained by subtracting the established memory area from the entire rendering memory area (see, for example, Japanese Laid-Open Patent Publication Nos. 2007-079934, 2000-238349, 2001-047673, and 2009-212826.
According to the conventional techniques, if an image is generated for each area, the memory capacity of a buffer temporarily storing a rendering command and an image may decrease. As a result, the writing of all the rendering commands to the buffer may become impossible, making proper rendering of an image difficult.